1. Field of the Invention
The invention pertains to a rotor of an ultrasonic test device for rotationally symmetrical test specimens, especially tubes, in which the rotor holds a probe carrier, which a) is arranged in a radial borehole, b) contains at least one probe, c) is mounted in such a way that it can be moved longitudinally in the direction of the axis of the borehole, and d) is tightly sealed in the borehole.
2. Prior Art
Test devices of this type are already well known for testing along the entire length of the test specimen and/or only for testing the end regions of a test specimen. Testing over the entire length of the test specimen is generally performed in continuous operation; the rotor remains fixed in its position as it rotates, and the test specimen is moved axially through the rotor along its longitudinal axis. For general information on the state of the art, the reader is referred to the book: J. and H. Krautkraimer, Werkstoffprufung mit Ultraschall [Material Testing with Ultrasound], 5th Ed., Springer Verlag, especially the section entitled "Tubes," which describes test systems for tubes.
Test devices of this kind are intended for rotationally symmetric test specimens of a general type, including not only round material, especially tubes and bars, but also material with regular polygonal cross sections, such as hexagonal bars. In this connection, see DE-A-38 03 151 and the unpublished document DE-A-39 08 967.
A rotor of the type mentioned above is used in the prior-art rotation test system for tubes between 20 and 180 mm in diameter, type ROT 180, manufactured by Krautkraimer GmbH & Co. Its two end regions are sealed from the test specimens in such a way that the central borehole of the rotor can be filled with water or other suitable probe-to-specimen contact fluid. The probe carrier is movably mounted in a radial borehole of the rotor arranged transverse to the axis of the test specimen. The probe carrier itself is designed as a type of piston. Test specimens of varying diameters can be systematically positioned by radial movement. In addition, the probe can be retracted to a protected position before a test specimen is run in. The central borehole is also sealed radially towards the outside, in the region of the probe carrier, by a seal between the borehole and the probe carrier. This also prevents contact fluid from escaping radially to the outside.
This previously known device can detect longitudinal and cross-sectional errors, and wall thickness can also be determined. Oblique errors in the test specimen cannot be reliably determined.